Reinforced plastic valve

ABSTRACT

A reinforced plastic valve includes a generally cylindrical major body portion which is at least partially formed of a plastic material. The major body portion has an axially extending interior chamber. A pair of flow lines intersect the major body portion and the interior chamber thereof. A plug is mounted in the chamber and is selectively rotatable to control flow of fluid through the flow lines. The major body portion includes a reinforcing sleeve formed of metal which is encased within the plastic major body portion to surround the interior chamber.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of copending application Ser. No.483,924 filed on Feb. 23, 1990 U.S. Pat. No. 4,988,077, which is acontinuation of Ser. No. 308,787 filed Feb. 8, 1989, now abandoned,which is a continuation of Ser. No. 873,712 filed on June 12, 1986, nowabandoned, which is a continuation of Ser. No. 740,228, filed on June 3,1985, entitled "Reinforced Plastic Valve", now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a reinforced plastic valve and, morespecifically, to such a plastic valve which should be capable ofoperating at higher pressure ratings for an extended period of time.

2. Description of the Prior Art

Plastic valves, such as those disclosed in U.S. Pat. Nos. 4,014,513;4,171,711; 4,234,011; and 4,488,741, have recently been satisfactorilyand successfully employed for the flow control of numerous types offluids in various piping systems and in a wide range of environmentalconditions. However, because of the nature of plastic, there haveheretofore been some limitations on the amount of fluid pressure whichshould be allowed in systems which employ plastic valves. For example,it has been found that, when various plastic valves have been utilizedin systems which have a relatively high operating pressure, after anextended period of time, the valve plug and/or valve body can experience"creep" which alters the design dimensions of the valve and/or plug todecrease its overall efficiency and reliability.

"Creep" can be defined as progressive strain without increased stress.If one is free to select alternative materials of construction, it ispossible to eliminate any real concern for "creep". However, there areinstances where the plastic body material must be identical to that ofthe piping system. For example, if the body is to be fused to the pipesin the system, the same material is required for a proper union. Thepiping could display high "creep" characteristics and still be reliablewhile the same "creep" in the body could alter its dimensions and reducethe reliability of sealing around the plug which prevents leakage andsealing at the valve seat which controls flow through the valve.

Although not specifically related to the type of valve of the presentinvention, U.S. Pat. No. 3,092,365 discloses a rubber plug for a valvewhich is basically formed around and reinforced by an internal metalstructure. Other types of valves have employed inserts in various typesof closure members and in various areas of the valve body to generallysolve different problems than that of "creep" as described hereinabove.For example, U.S. Pat. No. 3,133,722 discloses a sleeve liner which canbe made of plastic material but is intended to serve as a backingmaterial for a tapered plug member which is primarily intended tofunction as the closure device for the valve. U.S. Pat. No. 4,303,223discloses valve facing strips of a fire hydrant valve which areprimarily intended to provide a reliable, low friction working surfacefor the axial movement of the valve disclosed therein.

Additional patents disclose some form of sleeve or reinforcing elementwhich are not primarily intended to strengthen the valve body but areinstead intended to insure proper sealing of the valve during closure.For example, U.S. Pat. No. 3,061,269 discloses an internal sleeve whichcan be made of numerous types of material but is primarily intended toprovide a surface having a low-coefficient of friction for the rotationof the valve closure member disclosed therein. Similarly, U.S. Pat. Nos.3,244,389 and 3,398,925 disclose ball valves which have annularreinforcing means at the edge seals thereof to insure that propersealing is maintained against the surface of the ball to prevent theloss of fluid from the flow passages thereof.

U.S. Pat. No. 3,091,428 discloses a metallic ball valve and U.S. Pat.Nos. 3,192,945 and 3,913,610 disclose metallic butterfly valves whichare primarily intended for use in metal piping systems. The ball valveof U.S. Pat. No. 3,091,428 includes a central cylindrical ring sectionwhich primarily supports the ball and to which identical cups are joinedto form the composite valve. Similarly, the butterfly valves of U.S.Pat. Nos. 3,192,945 and 3,913,610 disclose cylindrical metallic sleevesor body portions which primarily rotatably support the butterfly closuremembers thereof. These valves include the provision of a lining orinterior coating for the cylindrical metallic portion which is formed ofresiliant rubber-like, plastic, or synthetic material to provide thesleeve with erosion and/or corrosion protection.

More significantly, U.S. Pat. No. 4,348,006 discloses a butterfly-typevalve having a plastic body portion with a valve seat formed by a metalsleeve molded within and sealed to the plastic valve body portion withan annular rubber sleeve insert vulcanized to the metal sleeve. Themetal sleeve is intended to prevent migration or "creep" of theelastomeric insert but additional sealing means between the metal sleeveand the plastic body portions is employed to insure that there will beno fluid leakage therebetween.

Finally, although not intended to reinforce the valve body thereof or toqualify the valve for use with fluids operating at higher pressures,U.S. Pat. No. 3,526,386 discloses a plastic valve having a metallicsleeve which is inserted in and embedded within the flow line thereof.The sleeve is said to "reinforce" the flow line but is primarilyutilized to provide a stronger, reinforced coupling means for installingthe plastic valve within a piping system.

Consequently, there remains a need for providing a plastic valve whichincludes means for insuring that the valve can be satisfactorilyemployed in fluid systems of higher pressure without any detrimentthereto over an extended period of time.

SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided a reinforcedplastic valve including a generally cylindrical major body portion atleast partially formed of a molded plastic material and having anaxially extending interior chamber. A pair of flow lines intersect themajor body portion and the interior chamber thereof. A flow isolationmember is mounted in the chamber and selectively movable to control theflow of fluid through the flow lines. The major body portion includesreinforcing means formed of a reinforcing material stronger than themolded plastic material embedded within said molded plastic material toat least partially surround the interior chamber.

Also in accordance with the present invention, there is provided areinforced plastic valve body structure including a generallycylindrical major body at least partially formed of a molded plasticmaterial and having an axially extending interior chamber which iscapable of receiving a movable flow isolation member therein. A pair offlow lines intersect the body and the body includes reinforcing meansformed of a reinforcing material stronger than the molded plasticmaterial embedded within said molded plastic material to at leastpartially surround the chamber.

Further, in accordance with the present invention, there is provided amethod of forming a generally cylindrical valve body including the stepsof forming a sleeve of reinforcing material into a generally cylindricalshape. The sleeve is installed within a valve body mold. Plasticmaterial is injected into the mold to at least partially surround thesleeve. The molded plastic material is allowed to set to retain thesleeve within the valve body.

Accordingly, it is an object of the present invention to provide a valvewhich includes a plastic body which is reinforced to allow the valve tobe utilized in fluid systems of higher pressure for an extended periodof time without any loss of reliability thereof.

It is a further object to provide such a valve where the body can beformed of a particular plastic material which is identical to that whichis considered appropriate for the piping system to enable the body to beproperly fused to the pipe.

It is another object of the invention to provide a method of formingsuch a valve by installing a sleeve of reinforcing material at leastpartially embedded within the plastic material of the body thereof.

These and other objects of the present invention will be more completelydisclosed and described in the following specification, the accompanyingdrawings, and the appended claims.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevational view partially in section of a preferred valveincluding various features of the invention.

FIG. 2 is a view of the preferred valve as seen along 2--2 in FIG. 1.

FIG. 3 is a sectional view of the preferred reinforcing sleeve orientedin a manner similar to its orientation in FIG. 1.

FIG. 4 is a view of the preferred sleeve as seen along line 4--4 of FIG.3.

FIG. 5 is an elevational view of the preferred sleeve as seen along line5--5 of FIG. 4.

FIG. 6 is an exploded view partially in section of the preferred sleeveincluding its method of formation within a plastic valve body mold andvarious features of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

As seen in FIG. 1, a preferred valve 10 is primarily formed of moldedplastic and includes a valve body structure 12 having a generallycylindrical body 14 with an axially extending interior chamber 16. Apair of flow lines 18 of the body structure 12 are preferably integrallyformed with and intersect the body 14 and include flow passages 20thereof which intersect the chamber 16. A rotatable flow isolationmember in the form of a plug 22 is mounted within the chamber 16 to becapable of being selectively positioned to allow or prevent flow throughthe flow passages 20.

Specifically, as seen in FIG. 1, the plug 22 includes a transverseopening 24 therethrough to allow flow through the flow passages 20 andopposing seats 26 which can be aligned with the passages 20 when theplug 22 is rotated to prevent the flow of liquid therethrough. The plug22 includes a handle 28 and at least one radially extending rotationalstep element 30 which will be discussed in detail hereinbelow. Further,the lower end 32 of the plug 22 includes a groove and retaining means 34for preventing withdrawal of the plug 22 from the chamber 16 after ithas been installed within the body portion 14. A sealed bottom 36 isadded to the body portion 14 after installation of the plug 22 thereinto prevent dirt or ice from forming at the bottom of the valve 10 andinterfering with the rotation of the plug 22. The preferred plug 22 isprovided a plurality of O-ring seals 38 to primarily retain fluid withinthe flow passages 20 and the transverse opening 24 of the plug 22 andprevent leakage at the top or bottom of the plug 22 during normal use ofthe valve 10. A sealing ring 40 is also provided to the top of the valve10 to prevent the ingress of fluid or contaminates into the chamber 16around the top of the plug 22. If "creep" were allowed to occur to thebody 14, proper sealing contact between the O-ring seals 38 and seats 26and the chamber 16 could not be maintained and leakage through the valve10 and to the atmosphere could occur.

As seen in FIG. 2, the preferred plug 22 includes two radially extendingrotational stop elements 30 which are shown in a position for allowingflow through the valve 10. The rotational stop elements 30 are preventedfrom rotation in a clockwise direction by respective abutting contactwith the ends 42 of a pair of axially extending sectors 44 of the body14. Rotation of the plug 22 in a counter-clockwise direction would causethe rotational stop elements 30 to make contact with the other ends 46of the axially extending sectors 44 of the portion body 14 to insurethat the seats 26 are properly aligned with the flow passages 20 whenthe valve 10 is closed. It should be noted that each of the sectors 44extends less than ninety degrees to accommodate for the thickness of thestop elements 30 while allowing a full ninety degree rotation of theplug 22. Clearly, the sectors 44 and stop elements 30 might be orientedto any circumferential location around the plug 22 and body portion 14as long as the opening 24 and seats 26 will be properly alignable withthe flow passages 20. It would also be obvious to alter the preferredvalve 10 to include only one stop element and one sector ofapproximately two hundred-seventy degrees for similar limitations on therotation of the plug.

As thus described, the preferred valve is similar to the valve disclosedin U.S. Pat. Nos. 4,014,513; 4,171,711; 4,324,011; and 4,488,741.Although the valves disclosed therein have been satisfactorily employed,the preferred valve 10 includes features which could accommodate ahigher pressure rating while being formed of a plastic material which isidentical to that selected for the piping system in which it is to beemployed. As mentioned hereinabove it has been found that when someplastic valves are subjected to higher operating pressures over anextended period of time, the body can experience "creep" where thedesign dimensions tend to change to interfere with the overall integrityof the plug as installed in the valve body and reduce the efficiency ofthe sealing of the valve. Accordingly, the preferred valve 10 includes apreferred portion body portion 14 which includes reinforcing meansformed of a reinforcing material which is stronger than the moldedplastic material.

The preferred reinforcing means is in the form of a sleeve 48 whichextends around the body 14. As best seen in FIGS. 3, 4, and 5, thepreferred sleeve 48 is formed of metal and is generally cylindrical tocompletely encircle the body 14. A pair of openings 50 are formedthrough the sleeve 48 and are to be aligned with the flow passages 20 ofthe flow lines 18.

Additionally, it will be noted that the preferred sleeve 48 includesaxially extending portions 52 at the upper end thereof which portions 52will lie within the pair of axially extending sectors 44 of the bodyportion 14. As a result, the axially extending portions 52 each includeends 54 which are aligned with the ends 42 of the sectors 44 and ends 56which are aligned with the ends 46 of the sectors 44. As a result, withthe sleeve 48 properly embedded within the body 14, the sleeve 48 willtend to reinforce the body 14 and further insure that there is adequatestrength in the axially extending sectors 44 for properly serving as ameans to limit rotation of the plug 22 throughout the life of the valve10. In fact, it is significant that the sectors 44 be sufficientlystronger than the stop elements 30 to insure that the stop elements 30will be cleanly severed from the plug 22 if one tries to force therotation of the plug 22 by the sectors 44. It is better for the stopelements to be cleanly removed than to allow forced rotation of the plug22 to result in its being directly damaged in a manner which wouldinterfere with its ability to selectively control flow through thevalve.

As shown in FIGS. 1 through 5, it should be clear that the preferredsleeve 48 is at least partially encased within the plastic material ofthe body 14. In other words, the sleeve 48 will properly addreinforcement to the body 14 but will not generally be exposed to theenvironment or to the fluid within the flow passages 20 or the interiorchamber 16. Since it is not exposed to the fluid in the valve 10, thereis no need to be concerned with any leakage around the sleeve 48 whichmight otherwise occur. Further, since the preferred reinforcing sleeve48 does not extend to the interior surface of the interior chamber 16,the preferred plug 22 will rotate and provide sealing as if it wereinstalled within an entirely plastic body 14.

As thus described, it is expected that the reinforcing sleeve 48 willprevent creep which may otherwise have existed in the major body portion14. It is also expected that the sleeve 48 will be properly retainedwithin the major body portion 14 by the incasement of the sleeve 48within the plastic material of the major body portion 14. However,should there turn out to be some localized movement of the plasticmaterial of the major body portion 14, it be possible to provide roundededges for the openings 50 to insure that no cracks or other failure ofthe plastic material develops at the edges of the holes 50.Additionally, although the sleeve 48 should remain in place since it isencased in the molded plastic material, an alternative configurationcould include a plurality of radially extending holes at variouslocations around the sleeve 48 to cause the plastic material to flowtherethrough when the body 14 is being formed by molding. Since theplastic material may not directly adhere to the metal of the sleeve 48,the additional holes would further insure that there is a completeincasement of the sleeve 48 within the plastic material. With theplastic material extending through such a plurality of holes in thesleeve 18, the sleeve 48 would be further secured within the body 14 toresist any rotational forces created by the stop elements 30 duringrotation of the plug 22.

To provide the valve 10 with the included reinforcing sleeve 48, thepreferred method of forming the valve body structure 12 includes meansfor insuring that the sleeve 48 is properly supported and orientedduring the plastic valve molding process. Specifically, as seen in FIG.6, a bottom core 58 and a top core 60 of the basic valve body mold areutilized to properly support and orient the preferred sleeve 48.Additional portions of the valve body structure mold have beeneliminated from FIG. 6 in order to be able to properly demonstrate thoseportions which are essential to an understanding of the overall methodof forming the valve body structure 12. For example, the valve body moldwould preferably includes a pair of passage cores for forming the flowpassages 20 which passage cores intersect with and join the bottom core58 and top core 60. Lastly, the valve body mold primarily includes anexternal mold which is formed of two halves for the formation of theexterior of the valve body 12. It should be understood that theinjection molding of plastic material of the type used to form thepreferred valve body 12 is well known in the art. For example, if onewere to provide any of the plastic valves mentioned as the prior arthereinabove, it would be quite common to inject plastic material into avalve body mold of the general type described and to allow the plasticmaterial to set prior to disassembly of the mold and removal of thecores therefrom.

However, in order to specifically support and orient the sleeve 48, thepreferred sleeve 48 includes four evenly-spaced notches 62 in the loweredge surface 64 thereof. The bottom core 58 includes a shoulder 66 on anupwardly extending cylindrical portion 68 thereof for receipt of thelower edge surface 64 of the sleeve 48 thereon. The shoulder 66 has fourevenly-spaced tabs 70 which are alignable with the notches 62 forrespectively receiving them thereon. Consequently, with the sleeve 48installed on the cylindrical portion 68 of the bottom core 58, thesleeve 48 is concentrically positioned on the core 58 and separated froma center portion 72 thereof which is intended to partially form theinterior chamber 16. Further, because of the orientation of the notches62 and the tabs 70, the sleeve 48 can be positioned on the bottom core58 with the openings 50 properly aligned for the formation of the flowlines 18.

Once the sleeve 48 is properly supported by the bottom core 58, the topcore 60 can be joined to the bottom core 58 as the center portion 74thereof combines with the center portion 72 of the bottom core 58 tocomplete the form needed for the interior chamber 16. The top core 60includes circumferential recessed portions 76 for receipt of the axiallyextending portions 52 of the sleeve 48 for the eventual formation of theaxially extending sectors 44 of the body 14.

After the bottom core 58 and the top core 60 are joined in this mannerwith the sleeve 48 properly positioned therebetween, the openings 50 ofthe sleeve 48 are aligned with a pair of cavities 78 at opposite sidesof the combined center portions 72, 74. The cavities 78 are intended toreceive the interior end of the passage cores mentioned hereinabove. Itshould be clear that the passage cores could be formed as a single longcore extending through the bottom core 58 and the top core 60 so thatthe cavities 78 would alternatively extend all the way therethrough. Ineither case, sleeve 48 is aligned with the passage cores to allow theformation of the flow passages 20 of the flow lines 18. When theexterior halves of the valve body mold are fully installed, as generallyrepresented by the dotted lines 80 to show their relationship to thecores 58, 60, the exterior walls of the body 14 will be formed with anoutside diameter larger than the exterior diameter of the sleeve 48.Accordingly, sufficient plastic material will be formed around theexterior of the sleeve 48 to primarily encase the sleeve 48 within thepreferred body 14. Since the passage core and the exterior halves of thevalve body mold does not make any contact with the sleeve 48, the sleeve48 is surrounded by the plastic material at all locations other thanthose where there is direct contact with the cores 58, 60. Consequently,the sleeve 48 is located radially within the cylindrical wall of thebody 14 to include the plastic material internally and externallythereof.

It should be clear that, after the entire valve body mold is assembled,plastic material can be injected into the mold to at least partiallysurround the molded sleeve 48. After the plastic material has beenallowed to set and the exterior mold and interior cores are removed, thesleeve 48 will be retained within the molded valve body structure 12.

Although the preferred sleeve 48 is primarily intended to reinforce thebody 14 throughout use of the valve 10, it is possible that the sleeve48 may provide an added benefit during formation of the body 14. It hasbeen found that when a body without an encased sleeve has been molded inthe manner generally described hereinabove, it is not uncommon for thebody to be slightly warped upon removal from the mold with the chamberthereof not having a truly cylindrical shape. As a result, the chambermust be machined to provide the required shape for proper receipt of aplug therein. The sleeve 48 being employed in the method of formation ofthe body 14 as described above could completely eliminate this requiredstep and should, at the least, reduce the amount of machining that maybe required. Further, if there is no need for such machining, it hasbeen found that the interior surface of the chamber as formed by thebody mold has excellent characteristics for direct installation of theplug therein.

Further, it would clearly be possible for various alterations to be madeto the preferred embodiment described hereinabove without departing fromthe scope of the invention as claimed. For example, it might beadvantageous to include only one notch at a lower edge surface of thesleeve to mate with only one tabl on the bottom core to insure thatthere is only one possible orientation of the sleeve relative to thebottom core. Additionally, although the "bottom core" was used toprimarily support the sleeve 48 during the formation of the preferredvalve body structure 12, it would be possible for either a bottom or atop core to be properly configured for this purpose while still fallingwithin the scope of the invention as claimed.

Although the method of providing the preferred valve body structure 12is expected to properly encase the sleeve 48 within the molded plasticmaterial, it should be recognized that the bottom core or the top corecould be slightly altered to further surround the end edges of thesleeve 48 with plastic material. As one example of any number of ways inwhich this could be accomplished, the shoulder 66 near each of theevenly spaced tabs 70 could be configured to discontinue a shortdistance from the tabs 70 to cause the lower edge surface 64 of thesleeve 48 to be separated from any portion of the bottom core 58. Withthe major circumference of the lower edge surface 64 being separatedfrom any portion of the bottom core 58, the molded plastic material willprimarily surround and encase the major circumference of the lower edgesurface 64. Such a configuration would still fall within the scope ofthe invention as claimed since the sleeve would still include agenerally radially extending surface which would be installed on asleeve supporting surface of the valve body mold even though thesupporting surface would be circumferentially smaller.

Still further, it should be clear that the preferred sleeve 48 is simplyone embodiment which could be utilized to practice the invention asclaimed. Specifically, it would be possible for the reinforcing sleeve48 to be made of some other material while still satisfying the basiccriteria of reinforcing the body 14. Additionally, the sleeve need notbe made to completely encircle the body 14 and could alternatively bemade of some sheet material which could be formed to only partiallyencircle the body portion 14. For example, it might be desirable to formthe reinforcing sleeve from some sheet metal and simply roll thepre-formed sheet material to only at least partially surround thechamber 16 above and below the flow lines 18. In fact, with some othertype of means for supporting a reinforcing sleeve means during analternative method of forming the major body, it would be possible fortwo separate partially encircling bands of metal to be installed withinthe interior of the body 14 to effectively prevent any circumferentialexpansion of the body 14 as might occur over an extended period of timeat higher pressures. Although the figures do not show such upper andlower bands of reinforcing material separately in the valve 10, they areshown in the form of corresponding upper and lower parts of thepreferred sleeve 48. Additionally, although it is clear from thecylindrical shape of the preferred body 14 that it would be appropriatefor the sleeve 48 to have a cylindrical shape, some other type of shapecould be provided if such shape would still reinforce a body of asimilarly plastic valve. As a result, numerous alterations could clearlybe made to the preferred embodiment described hereinabove withoutdeparting from the scope of the invention as claimed.

According to the provisions of the patent statutes, we have explainedthe principle, preferred construction and mode of operation of theinvention and have illustrated and described what we now consider torepresent its best embodiments. However, it should be understood that,within the scope of the appended claims, the invention may be practicedotherwise than as specifically illustrated and described.

We claim:
 1. A reinforced plastic valve comprising:a generallycylindrical unitary valve body formed of a molded plastic materialhaving deformable creep properties under pressure, said unitary valvebody having a generally cylindrical axially extending interior chamber,said valve body interior chamber having an inner cylindrical wall; apair of flow lines extending into said interior chamber of said valvebody; a flow isolation member having valve seats and a generallycylindrical configuration throughout its length, said flow isolationmember mounted in said generally cylindrical chamber and rotatablymovable to control the flow of fluid through said flow lines; sealmembers positioned on said flow isolation member above and below saidflow lines in sealing contact with said valve body inner cylindricalwall; said valve body including a reinforcing member that is strongerthan said plastic material forming said valve body, said reinforcingmember having deformable creep properties substantially less than thecreep properties of said plastic material forming said valve body, saidreinforcing member having a generally cylindrical shape with an innersurface and an outer surface, said reinforcing member having a pluralityof radially extending apertures at various locations around saidreinforcing member, said plastic material forming said valve bodyextending through said apertures in said reinforcing member andconnecting said plastic material forming said valve body on both sidesof said reinforcing member; said reinforcing member preventing creep ofsaid valve body and providing dimensional stability to said valve bodyto thereby maintain sealing contact between said seal members and saidvalve body inner cylindrical wall; and said flow isolation member havingat least one radially extending stop means and said reinforcing memberhaving at least one axially extending shoulder, said stop means arrangedto abut said valve body adjacent said axially extending shoulder andlimit rotation of said flow isolation member, said other portions ofsaid plastic material forming said valve body and extending through saidapertures in said reinforcing member preventing rotation of saidreinforcing member relative to said valve body when torque is applied tosaid valve body and said reinforcing member by said flow isolationmember stop means.
 2. A reinforced plastic valve comprising;a generallycylindrical unitary valve body formed of a molded plastic materialhaving deformable creep properties under pressure, said unitary valvebody having a generally cylindrical axially extending interior chamber,said valve body interior chamber having an inner cylindrical wall; apair of flow lines extending into said interior chamber of said valvebody; a flow isolation member having valve seats and a generallycylindrical configuration throughout its length, said flow isolationmember mounted in said generally cylindrical chamber and rotatablymovable to control the flow of fluid through said flow lines; sealmembers positioned on said flow isolation member above and below saidflow lines in sealing contact with said valve body inner cylindricalwall; said valve body including a reinforcing member that is strongerthan said plastic material forming said valve body, said reinforcingmember having deformable creep properties substantially less than thecreep properties of said plastic material forming said valve body, saidreinforcing member having a generally cylindrical shape with an innersurface and an outer surface, said reinforcing member having a pluralityof radially extending apertures at various locations around saidreinforcing member, said reinforcing member embedded during the moldingprocess within said molded plastic forming said valve body and saidplastic material forming said valve body extending through saidapertures in said reinforcing member and connecting said first portionof said plastic material forming said valve body with said secondportion of said plastic material forming said valve body; said flowisolation member having at least one radially extending stop means andsaid reinforcing member having at least one axially extending shoulder,said stop means arranged to abut said valve body adjacent said axiallyextending shoulder and limit rotation of said flow isolation member,said other portions of said plastic material forming said valve body andextending through said apertures in said reinforcing member preventingrotation of said reinforcing member relative to said valve body whentorque is applied to said reinforcing member by said flow isolationmember stop means; and said reinforcing member preventing creep of saidvalve body and providing dimensional stability to said valve body tothereby maintain the sealing contact between said seal members and saidvalve body inner cylindrical wall.